While thin film solar cells, such as CdS/CdTe solar cells, made according to methods known in the art have achieved efficiencies near 10%, further improvements in efficiency require increased fill factor. In order to increase the fill factor of a cell the electrical resistance at the contact between the CdTe semiconductor layer and the contact layer needs to be reduced. A measure of this resistance is the slope of the current-voltage curve at the open circuit voltage point. Moreover, high efficiencies have been mostly obtained using gold for the contact metal. However, gold is not only an expensive material, but there is evidence that cells utilizing gold contacts are not stable for long periods of time. Therefore, there is a need for a fabrication process that provides for increased fill factor and permits substitution for gold with other metals. The art also teaches various etches for preparing the surface of CdTe before forming the contact. However, wet etching may not always be desirable or feasible for fabricating thin film cells.